Knowledge Bank

Three new bands of CoH and five new bands of CoD have been observed using laser excitation in the visible and near-infrared, following reaction of cobalt atoms with $H2$ or $D2$ under supersonic jet-cooled conditions. All the new bands, together with two reported previously by $Varbergetal.1$ are shown to belong to a single electronic transition with an origin near $12400cm-1$, here designated $A\prime 3\Phi 4-X3\Phi 4$. High resolution spectra of the (0,0) bands of both CoH and CoD reveal extensive hyperfine structure associated with the $\mathrm{<mrow\; data-mjx-texclass="ORD">59</mrow>}Co$ nucleus (I = 7/2), which shows that the electron configuration of the $A\prime 3\Phi 4$ state is $(4s\sigma )1(3d\delta )3(3d\pi )3(3d\sigma )1$. Wavelength resolved fluorescence from one of the CoD bands gave the $\Omega =4-3$ spin-orbit interval for the $X3\Phi$ state as $729cm-1$ and confirmed the presence of a lowlying $\Omega =3$ electronic state near $2400cm-1$.